I would guess they put on the two different wheels to show how they look on a SL500. If you look at the 4th pic or so the car doesnt have a license plate but has a plate for the shop. Maybe they just threw it on for *****s and Giggles....

its probably a demo car for shows etc. I saw a few cars at the Atlanta Auto Show with a diff. set of wheels on each side.Either way that car is sicker than sick. Brandon, you'll pay for posting these pics

And less than perfect offests for custom wheels. The rears look like they could come out 0.5-1"!!!

HRE makes two different wheel offsets for these cars- one for guys who don't want to roll the fenders (like most of the WHINERS on this board), and one for those who want a more aggressive, european look (fender rolling required).